A convenient stereoselective synthesis of β-lactams from β-hydroxy-α-thioalkylesters prepared from Michael/aldol tandem reaction or stereoselective addition of thiols to the Baylis–Hillman adducts
作者:Akio Kamimura、Rie Morita、Kenji Matsuura、Hiromasa Mitsudera、Masashi Shirai
DOI:10.1016/j.tet.2003.10.035
日期:2003.12
A convenient stereoselective synthesis of β-lactams from thio-Michael/aldol tandem adduct is described. syn-Selective tandem reaction followed by amidation and intramolecular SN2 reaction provided β-lactams in diastereomerically pure form. The tandem reaction with aliphatic aldehydes, on the other hand, afforded a mixture of diastereomers of corresponding tandem adducts in about 3:1 ratio so that the
描述了由硫代迈克尔-迈克尔/醛醇双键加合物方便地立体选择性合成β-内酰胺。syn-选择性串联反应,然后进行酰胺化和分子内S N 2反应,提供非对映体纯形式的β-内酰胺。另一方面,与脂族醛的串联反应以约3∶1的比例提供了相应的串联加合物的非对映异构体的混合物,使得转化为β-内酰胺提供了非对映异构体的混合物。作为制备串联加合物的另一种方法,开发了将脂肪族硫醇立体选择性迈克尔加成到Baylis-Hillman加合物中的方法。立体选择性对羟基上的保护基敏感,TBS保护带来了最成功的合成选择性形成串联加合物。该方法可用于Baylis-Hillman加合物的酮衍生物,但未观察到腈-Baylis-Hillman加合物的选择性。加合物的类似转化立体选择性地提供了所需的β-内酰胺。